To do so, HSH looked at the National Association of Realtors’ fourth-quarter data for median home prices and HSH.com’s fourth-quarter average interest rate for 30-year, fixed-rate mortgages to determine how much money homebuyers would need to earn in order to afford only the principal and interest payment on a median-priced home in their market. (They did not account for property taxes, insurance, and other expenses — read their methodology here.)